1. Technical Field
Example embodiments relate to semiconductor devices and methods of forming semiconductor devices.
2. Description of the Related Art
Dynamic random access memories (DRAM) consist of unit cells including one transistor and one capacitor. Reducing chip size is important when attempting to increase the integration of a DRAM device. Chip size reduction may be realized by a new cell structure. A 6.3F2 structure has been introduced as such a new cell structure.
In a 6.3F2 structure, a storage contact and a storage contact pad are not precisely aligned with each other. As a result, the center axis of the storage contact and the center axis of the storage contact pad are not located on the same straight line. However, having a sufficient contact area between the storage contact and the storage contact pad is important. Thus, a process of enlarging the contact hole that is filled with the storage contact may be used to increase the contact area.
A metal silicide layer may be disposed between a bit line contact and a bit line contact pad to reduce the resistance between the bit line and the bit line contact pad. However, in the process of enlarging the contact hole, the metal silicide layer may be melted by the etching solution. As a result of the melting of the metal silicide layer, voids may occur between the bit line and the bit line contact pad.